metrics explanation needed

[hopewise]

When I run sudo systemctl status I got:

Service: sidekiq-critical [Up/16399]
  cpu:system                          0.1%
  cpu:total_system                    0.0%
  cpu:total_user                      0.0%
  cpu:user                            2.0%            90%
  memory:rss                          367.52m

Service: sidekiq-leads [Up/16603]
  cpu:system                          3.5%
  cpu:total_system                    0.0%
  cpu:total_user                      0.0%
  cpu:user                            49.6%           90%
  memory:rss                          1001.32m

Service: sidekiq-low [Up/16291]
  cpu:system                          0.5%
  cpu:total_system                    0.0%
  cpu:total_user                      0.0%
  cpu:user                            15.8%           90%
  memory:rss                          995.02m

Service: sidekiq-others [Up/16608]
  cpu:system                          0.3%
  cpu:total_system                    0.0%
  cpu:total_user                      0.0%
  cpu:user                            7.8%            90%
  memory:rss                          501.09m

Service: sidekiq-salesforce [Up/16534]
  cpu:system                          0.1%
  cpu:total_system                    0.0%
  cpu:total_user                      0.0%
  cpu:user                            1.9%            90%
  memory:rss                          489.58m

my question is, why I see different cpu:user value for each process? although they are the same user deploy ? also, why cpu:system value is different for each process? aren't they all running on the same system? it might be dump questions, but explanation are highly appreciated, also, if you can point me to a source of knowledge if you may

Thanks

[mperham]

Because each process is executing different jobs and therefore using different amounts of resources.